Dental Crowns

A dental crown is a restoration that covers or caps a tooth, restoring it to its normal size and shape while strengthening and improving its appearance. Crowns are necessary when the tooth is broken down to the point where a filling will not be effective.

Benefits of Dental Crowns

A dental crown can be used for various reasons including covering discolored or misshapen teeth, and in conjunction with bridges and dental implants. Other benefits of dental crowns may include:

• Holding a cracked tooth together to prevent further damage
• Covering and supporting a tooth with a large filling
• Restoring a broken tooth

Dental Crown Procedure

The dental crown process takes place in two phases or appointments. At the first appointment, the tooth is prepared by filing or reshaping, so the crown can fit in securely and comfortably. The area around the tooth is numbed throughout the procedure with a local anesthetic. After the tooth is prepared, an impression is made of the teeth and gums using a paste or putty. The impression is then sent to a laboratory to make a custom crown, which usually takes two to three weeks. Patients are given a temporary dental crown until the permanent crown is ready.

At the second appointment, the new crown is inspected for proper fit and tooth color. The temporary crown is then removed and the new one is cemented onto the tooth.

Types of Dental Crowns

There are several different methods of crown restoration, each using a different crown material. Different types of crown material include:

Metal Crowns

Metal crowns are made entirely of a metal alloy that may include gold, platinum, palladium, or other elements. Compared with other kinds of crowns, metal crowns preserve more of the tooth structure. They withstand biting and chewing forces well and rarely chip or break. The biggest drawback of metal crowns is the metallic color.

Porcelain-Fused-to-Metal or PFM Crowns

PFM crowns can be color-matched to the teeth. Second only to all-ceramic crowns in appearance, porcelain-fused-to-metal crowns look like normal teeth. In some cases, the metal underlying the crown's porcelain can create a dark line. PFM crowns tend to wear down opposing teeth more than metal crowns. The crown's porcelain portion can also chip or break.

Resin Crowns

All resin crowns are the least expensive type of dental crown. The drawback is that they are more prone to chips and fractures than other crowns and tend to wear down over time.

Ceramic or Porcelain Crowns

These crowns provide the best natural color of all the dental crowns. They are not as strong as PFM or gold crowns, and they may wear down opposing teeth more than metal or resin crowns. Because they are the most cosmetically pleasing, they are commonly used for the front teeth.

Complications of Dental Crowns

Some patients experience increased sensitivity immediately after the procedure, particularly if the crowned tooth still has a nerve in it. For sensitivity to heat and cold, some patients are advised to use toothpaste for sensitive teeth. Other complications that may occur with dental crowns are:

Pain or Sensitivity When Biting

This usually means that the crown is too high on the tooth. If this is the case, the dentist will be able to fix the problem by adjusting the crown.

Chip in a Porcelain Crown

Resin can be used to repair the remaining crown. If the chipping is extensive, the entire crown may need to be replaced.

Loose Dental Crown

If the cement washes out from underneath the crown, bacteria can then leak in and cause decay. A dentist should be consulted to resecure the crown to alleviate the problem.

In some cases, a dental crown may fall off entirely. If this happens, contact the dentist immediately. The dentist may be able to replace the crown or create a new crown if necessary.

With proper oral hygiene, dental crowns can last from five to fifteen years. Patients should consult with their dentist to see if dental crowns are appropriate for their individual condition.

Additional Resources

• MedlinePlus
• National Institutes of Health
• Centers for Disease Control and Prevention
• Eunice Kennedy Shriver National Institute of Child Health and Human Development
• U.S. Department of Health & Human Services
• WebMD